Sealant Resin Composition Patent Application

ChangeBridge: Patent Apps - Batteries (H01M)

Published September 5th, 2023

Detected March 26th, 2026

Summary

The USPTO has published a patent application by MITSUI CHEMICALS, INC. for a sealant resin composition designed to resist whitening during stretching and maintain heat seal strength. The application details specific requirements for the composition's hardness and melt flow rate.

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What changed

This document is a USPTO patent application (US20260085218A1) filed by MITSUI CHEMICALS, INC. on September 5, 2023. The application describes a sealant resin composition comprising a specific 1-butene/ethylene copolymer and a propylene-based polymer. Key characteristics include a Shore D hardness between 44 and 80 and a melt flow rate (MFR) between 0.1 to 100 g/10 min, aimed at providing excellent stretch whitening resistance and heat seal strength.

As this is a patent application, it does not impose direct compliance obligations on regulated entities. However, companies involved in the development or manufacturing of sealant resins, particularly those used in battery applications (indicated by CPC classifications), should be aware of this potential new technology and its specific material property requirements. No compliance deadlines or penalties are associated with patent applications.

Source document (simplified)

← USPTO Patent Applications

SEALANT RESIN COMPOSITION, AND USE THEREOF

Application US20260085218A1 Kind: A1 Mar 26, 2026

Assignee

MITSUI CHEMICALS, INC.

Inventors

Takahiro MIZUMA, Manabu ITAKURA, Nozomi KAMIYA, Kiminori NODA, Makoto EGAWA

Abstract

The purpose of the present invention is to provide a sealant resin composition having excellent resistance to whitening during stretching, and good heat seal strength, as well as good heat seal strength after heat aging. The present invention relates to a sealant resin composition (X) including a 1-butene/ethylene copolymer (A) satisfying a specific requirement, and a propylene-based polymer (B), the resin composition satisfying the following requirements (X1) and (X1-2): requirement (X1): having a Shore D hardness measured in accordance with ASTM D2240 being in a range of 44 to 80; and requirement (X1-2): having a melt flow rate (MFR) measured at 230° C. and a load of 2.16 kg in accordance with ASTM D1238 being 0.1 to 100 g/10 min.